Fur treating composition and process



Patented Dec. 24, 1940 PATENT OFFICE FUR TREATIlgG COMPOSITION ANDaoonss William Page, Cranford, and Morris Lefkowitz, Irvington, N. J.

No Drawing.

'7 Claims.

The present invention is concerned with the production of fur which maybe readily processed into felt of improved quality. The invention moreparticularly is concerned with an improved so-called carroting processby which rabbit, hare, beaver, and similar types of fur are treated,utilizing as a carroting solution an aqueous mixture comprising a zincsalt, an oxidizing agent, and a hydrolyzing agent. In accordance withthe present process, a carroted fur is produced which may be readilyprocessed into a smooth, strong, tight felt which will exhibitsubstantially improved wearing qualities. Our process is particularlydesirable in that the resulting product is of a higher quality than hasheretofore been secured and that this product is secured in aneconomical and efilcient process which is entirely innocuous withrespect to the health of the operating personnel.

It is well known in the art to process animal fur, particularly rabbit,hare, beaver, and similar types of fur, by a carroting process whichgenerally comprises treating the fur with an aqueous solution ofmercuric nitrate and nitric acid. This solution is usually applied tothe fur while still on the pelt although it may be applied after removalof the fur from the pelt. The fur is then dried at temperatures rangingfrom atmospheric to temperatures as high as 250 F. or higher, dependingupon the nature of the fur and the type and quality of final treatedproduct desired. The drying conditions vary considerably, depending to alarge extent upon the particular fur being processed, the carrotingsolution employed, as well as upon general atmospheric and other relatedconditions. However, due to the fact that mercury and mercury salts aretoxic in nature and may adversely affect the health of the operatingpersonnel in contact with felting processes and related arts, it hasbeen suggested that various non-mercuric carroting solutions besubstituted for the mercuric carrotiug solutions. In general, thesemercury-free solutions comprise an oxidation agent, as for examplechloric acid, bromic acid, iodic acid, permanganic acid, hydrogenperoxide, and the like, and a hydrolyzing agent, such as sulfuric acid,acids of phosphorus,

or equivalent acids with function to duplicate.

the oxidation and hydrolyzing effects secured by the nitric acid presentin the mercuric nitrate solution.

The hydrolyzing agents in general are characterized by having a highionization value and by being relatively non-volatile at drying tem- 5peratures. Qesirable hydrolyzing agents, fur- Application February 10,1940, Serial No. 318,324

thermore, are relatively stable so that side reactions resultlng in theconsumption of the agent do not occur during the processing. Particularnon-mercurous carroting solutions which have been suggested are, forexample, a solution comprising an oxidation .agentsuch as permanganicacid and a hydrolyzing agent which is preferably sulfuric acid or acarroting solution in which the oxidizing agent is a peroxide, as forexample, hydrogen peroxide. These solutions, in general, 10 have notbeen commercially successful duein part to the fact that they have slowstarting and slow sizing characteristics. It is also known that althoughcertain desired results may be secured in the carroting process,provided the treating reagents are sufficiently strong and concentrated;Other deleterious factors are encountered in that the life of the fiberis adversely affected, particularly with respect to its wearing abilityand with respect to its ability to absorb 0 color. Furthermore, whenutilizing sulphuric acid as the hydrolyzing agent, increasing theconcentrations of the same will tend to cause formation of tarry matteron the surface of the fiber giving it a burnt appearance and renderingit 25 unsuitable for use. In order to overcome th disadvantages of thistype of carroting solution, numerous suggestions have been made forincorporating various inhibiting and catalytic agents into respectivenon-mercuric solutions which have not produced. material benefits,particularly with respect to duplicating the efiiciency of the mercuricnitrate solution and the uniform quality of the resulting product.

We have now discovered a non-toxic carroting solution which may beefliciently employed for the production of a carroted fur ofexceptionally high uniform quality. The carroted fur produced by ourprocess is' extremely stable and may be stored for longperiods of timewithout any substantial deterioration of the fiber occurring. Ourcarroted fur may be readily felted with an exceptionally low loss inweight during. the felting operation. Furthermore, the felted productproduced from our fur is smoothly and tightly interlaced, resulting inthe production of a fabric having exceptionally fine, natural lustre andresiliency of the fibers, which in turn contributes to the appearanceand wearingquality of the felt. Our felt is also characterized in thatit has the ability to absorb and indefinitely retain without fading alldye shades without objectionable overcast or other mottled efiects orbackground.

The carroting solution of our invention comp ses 8-. zinc salt, anoxidizing agent, and a hydrolyzingagent. Although the zinc salt maycomprise the chloride or the nitrate, the preferred zinc salt is thesulfate. The oxidizing agent may comprise any known satisfactoryoxidizing agent used in carroting processes, as for example, iodic acid,permanganic acid, hydrogen peroxide, and the like. However, in general,we prefer to employ hydrogen peroxide in combination with the zincsulfate. The hydrolyzing agent likewise may comprise any satisfactorymaterial which is generally characterized by having a high ionizationvalue and which is relatively non-volatile at the temperatures ofdrying, as for example, a sulphuric acid, hydrochloric acid, nitricacid, or an acid of phosphorus. In

general, however, we have found that particularly desirable results aresecured, provided zinc sulfate, hydrogen peroxide, and sulphuric acid beused in conjunction with one another.

The concentration, of the particular constituents in our carrotingcomposition may vary considerably depending upon reagents employed. Forexample when utilizing a preferred composition it is desirable that theconcentration of the zinc sulphate be in the range from about 2 to 10%by weight, particularly in the range from about 5 to 7%, that the weightconcentration of the-hydrogen peroxide based on a hundred volumesolution, be about equivalent to or several per cent higher than theweight concentration of the zinc sulphate; and that the weightconcentration of the sulfuric acid be about 40% to 60% greater than theconcentration of the zinc sulphate, based upon 66 Baum acid orequivalent. treating composition consists of an aqueous solution ofabout 6% by weight of zinc sulphate, about 8% by-weight of volumehydrogen peroxide, and about 9% by weight of 66 Baum sulfuric or itsequivalent.

The properties of'our solution may be somewhat varied and controlled bythe addition thereto of various inhibiting and catalyzing agents. Inthis regard we have further discov ered that the effectiveness anddesirability of our solution is considerably enhanced provided a lowionizable organic acid and for example acetic acid and the like beemployed in conjunction therewith, and that its value is furtherenhanced provided a ketone, particularly acetone, is also employed. Wehave also discovered that the waste, a loss of weight in felting, ismaterially reduced provided tannic acid be em- For example, a verysatisfactory centrations' of the same be from two to three times theweight concentration of the zinc sulphate. The preferred tannic acidconcentration is from about $3 to 8% weight per cent. A

particular desirable solution consists of from about 5 to 8% by weightzinc sulphate, 5 to 7% tannic acid, 12 to 25% of 28% acetic acid, 5 to l10% of 66 Baum sulphuric acid and from about 4 to 8% of 100 volumehydrogen peroxide.

In order to further illustrate the invention the following examples aregiven which should not be construed as limiting the same in any mannerwhatsoever:

Example Preferred carroting solution-A Weight per cent Zinc sulphate- 6Sulphuric acid, 66 Baum 9 Acetic acid, 28% 16 ,Hydrogen peroxide, 100volume solution 6 Preferred carroting solution- B Zinc sulphate 5Sulphuric acid, 66 Baum 9 Acetic acid, 28% 16 Hydrogen peroxide, 100yolume solution 6 Preferred carrotz'ng soZutionC Zinc sulphate H 5Sulphuric acid, 66 Baum 9 Acetone 16 Hydrogen peroxide, 100 volumesolution 8 Preferred carrotz'ng solution-D Zinc chloride 5 Acetic acid,28% 10 Hydrogen peroxide, 100 volume solution 6 Preferred carrot ingsolutionE Zinc sulphate 5 Tannic' acid 7 Acetic acid, 28% l5 Sulphuricacid, 66 Baum 7 Hydrogen peroxide, volume solution 4 The results securedwhen employing the respective solutions are as follows:

Felting process shrinking liercenft characteristics Carrotingcomposition Appearance of fur after treating, g

em We drying and cutting ff tir Machine Machine comlpen's feltingstflmgg A" B (mun 8) (minutes) (minutes) Commercial mercuric nitratecarrot.- Good yield, glossy, fibers cling ll 4 8 18 Very good. Commercal nonmercur c carrot, #1... Poor yield, dull, harsh appearance" 28 3%10 22 Fair. Commerc al nonmercur c carrot, #2-.. Fair yield, slightlydull appearance..-. 2% 4% 12 33 Do. Commerc al nonmercuric carrot, #3...Fair yield, iur darkened, some gloss 27 6% 18 50 Poor. Commercialnonmercuric carrot, #4... Poor yield. some gloss, pungent (odor) 24 5 /410 20 Do. Preferred carrot ng solution (A) Good yield, harsh feel 15 5/6 10 20 Good. Preferred carrot ng solution (B).. Good yield, glossy,fibers adhesive 17 5% ll 21 Very good. Preferred carrotlng solution (C)Good yield, some gloss, harsh feel"... 20 424 12 26 Good. Preferredcarrotlng solution (D) Good yield, some gloss, good appear- 21 6 12 24Fair.

, ance.

Preferred carroting solution (E) Good yield, glossy, fibers adhesive. 35% 10 20 Very good.

' N umber of times through machine for initial shrinking.

"Time required for shrinking to intermediate predetermined fixed size.

*Time required for shrinking to final predetermined fixed size.

ployed in conjunction with our solution. When employing acetic acid oracetone or equivalent reagents it is preferred that the weight con- Fromthe above-data it is apparent that the carroting solutions of thepresent invention possess distinct advantages and result in an imwith acarroting solution comprising zinc sul-- proved product. The feltedmaterial furthermore is apparently impregnated in a manner with zincwhich materially facilitates theshaping and sizing operations andresults in the production of a product of a fine texture and lustrehaving improved properties with respect to its ability to retain itsshape and wear for longer time period under extremely adverseconditions:

The process of the present invention is not to be limited by any theoryor mode of operation but only in and by the following claims by which itis desired to claim all novelty insofar as the prior art permits.

' We claim:

1. A composition for carroting fur comprising zinc sulphate, aceticacid, a peroxidizing agent and an hydrolyzing agent.

2. A composition as defined by claim the concentration of the zincsulphate is in the range from about 5% to 8% and the concentration ofacetic acid is in the range from about 12% 3. A process for theproduction of fur which may-be readily felted comprising treating fur 1in which phate, acetic acid, a peroxidizing agent and an hydrolyzingagent.

4. A process as defined by claim 3 in which the hydrolyzing agentcomprises sulfuric acid.

5. A composition for carroting fur comprising zinc sulphate, aceticacid, tannic acid, a peroxidizing agent and an hydrolyzing agent.

6. A compositionfor carroting fur comprising 5% to 8% by weight of zincsulphate, 5% to 7% of tannic acid, 12% to 25% by weight of 28% aceticacid, 5% to 10% of 66 Baum sulfuric acid, and from about 4% to 8% of 100volume hydrogen peroxide.

WILLIAM PAGE. MORRIS LEFKOWITZ.

